BMI Calculation for 5'5" and 120 lbs
For an individual who is 5'5" (165 cm) and 120 lbs (54.4 kg), the BMI is 20.0 kg/m², which falls within the normal/healthy weight range of 18.5-24.9 kg/m². 1, 2
Calculation Method
- BMI is calculated as weight in kilograms divided by height in meters squared 1, 3
- Height of 5'5" = 65 inches = 165 cm = 1.65 meters 1
- Weight of 120 lbs = 54.4 kg 1
- BMI = 54.4 kg ÷ (1.65 m)² = 54.4 ÷ 2.72 = 20.0 kg/m² 1, 3
- Alternative formula using pounds and inches: [120 lbs ÷ (65 inches)²] × 703 = 19.97 kg/m² 1, 3
Weight Classification
This BMI of 20.0 kg/m² is classified as normal/healthy weight, which is associated with the lowest risk for cardiovascular disease, diabetes, and overall mortality. 1, 2
- Normal/healthy weight range: BMI 18.5-24.9 kg/m² 1, 2
- For this height (5'5"), the healthy weight range is approximately 111-149 lbs 4
- Overweight begins at BMI ≥25.0 kg/m² (≥150 lbs at this height) 1, 2
- Obesity begins at BMI ≥30.0 kg/m² (≥180 lbs at this height) 1, 2
Clinical Significance
Individuals with BMI in the normal range (18.5-24.9 kg/m²) should maintain their current weight and avoid weight gain through regular monitoring and physical activity. 2
- Normal BMI is associated with lower cardiovascular event rates compared to overweight or obese categories 1
- Maintaining weight within the healthy BMI range reduces risk of multiple cancers, cardiovascular disease, diabetes, and overall mortality 4
- A 30-year cohort study of 273,843 persons demonstrated that those with BMI 18.5-24.9 kg/m² had the lowest mortality risk, while overweight (BMI 25-29.9) showed 1.1 times increased risk and obesity showed progressively higher risk 5
Important Caveats
BMI has limitations as it does not directly measure body fat or account for individual differences in muscle mass and body composition. 1, 2
- BMI has good specificity (90%) but low sensitivity (50%) for diagnosing excess adiposity 2
- Waist circumference should be measured alongside BMI for more complete risk assessment, with >35 inches in women indicating increased cardiovascular risk 1, 4
- For Asian populations, lower BMI thresholds apply (overweight ≥23 kg/m², obesity ≥25 kg/m²) due to higher body fat percentages and visceral adiposity at lower BMI values 1, 3